#  Copyright 2022 Google LLC
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
# flake8: noqa


# This file is automatically generated. Please do not modify it directly.
# Find the relevant recipe file in the samples/recipes or samples/ingredients
# directory and apply your changes there.


# [START compute_custom_machine_type_update_memory]
from __future__ import annotations

import sys
import time
from typing import Any

from google.api_core.extended_operation import ExtendedOperation
from google.cloud import compute_v1


def wait_for_extended_operation(
    operation: ExtendedOperation, verbose_name: str = "operation", timeout: int = 300
) -> Any:
    """
    Waits for the extended (long-running) operation to complete.

    If the operation is successful, it will return its result.
    If the operation ends with an error, an exception will be raised.
    If there were any warnings during the execution of the operation
    they will be printed to sys.stderr.

    Args:
        operation: a long-running operation you want to wait on.
        verbose_name: (optional) a more verbose name of the operation,
            used only during error and warning reporting.
        timeout: how long (in seconds) to wait for operation to finish.
            If None, wait indefinitely.

    Returns:
        Whatever the operation.result() returns.

    Raises:
        This method will raise the exception received from `operation.exception()`
        or RuntimeError if there is no exception set, but there is an `error_code`
        set for the `operation`.

        In case of an operation taking longer than `timeout` seconds to complete,
        a `concurrent.futures.TimeoutError` will be raised.
    """
    result = operation.result(timeout=timeout)

    if operation.error_code:
        print(
            f"Error during {verbose_name}: [Code: {operation.error_code}]: {operation.error_message}",
            file=sys.stderr,
            flush=True,
        )
        print(f"Operation ID: {operation.name}", file=sys.stderr, flush=True)
        raise operation.exception() or RuntimeError(operation.error_message)

    if operation.warnings:
        print(f"Warnings during {verbose_name}:\n", file=sys.stderr, flush=True)
        for warning in operation.warnings:
            print(f" - {warning.code}: {warning.message}", file=sys.stderr, flush=True)

    return result


def add_extended_memory_to_instance(
    project_id: str, zone: str, instance_name: str, new_memory: int
):
    """
    Modify an existing VM to use extended memory.

    Args:
        project_id: project ID or project number of the Cloud project you want to use.
        zone: name of the zone to create the instance in. For example: "us-west3-b"
        instance_name: name of the new virtual machine (VM) instance.
        new_memory: the amount of memory for the VM instance, in megabytes.

    Returns:
        Instance object.
    """
    instance_client = compute_v1.InstancesClient()
    instance = instance_client.get(
        project=project_id, zone=zone, instance=instance_name
    )

    if not (
        "n1-" in instance.machine_type
        or "n2-" in instance.machine_type
        or "n2d-" in instance.machine_type
    ):
        raise RuntimeError("Extra memory is available only for N1, N2 and N2D CPUs.")

    # Make sure that the machine is turned off
    if instance.status not in (
        instance.Status.TERMINATED.name,
        instance.Status.STOPPED.name,
    ):
        operation = instance_client.stop(
            project=project_id, zone=zone, instance=instance_name
        )
        wait_for_extended_operation(operation, "instance stopping")
        start = time.time()
        while instance.status not in (
            instance.Status.TERMINATED.name,
            instance.Status.STOPPED.name,
        ):
            # Waiting for the instance to be turned off.
            instance = instance_client.get(
                project=project_id, zone=zone, instance=instance_name
            )
            time.sleep(2)
            if time.time() - start >= 300:  # 5 minutes
                raise TimeoutError()

    # Modify the machine definition, remember that extended memory is available only for N1, N2 and N2D CPUs
    start, end = instance.machine_type.rsplit("-", maxsplit=1)
    instance.machine_type = start + f"-{new_memory}-ext"
    # TODO: If you prefer to use the CustomMachineType helper class, uncomment this code and comment the 2 lines above
    # Using CustomMachineType helper
    # cmt = CustomMachineType.from_str(instance.machine_type)
    # cmt.memory_mb = new_memory
    # cmt.extra_memory_used = True
    # instance.machine_type = str(cmt)
    operation = instance_client.update(
        project=project_id,
        zone=zone,
        instance=instance_name,
        instance_resource=instance,
    )
    wait_for_extended_operation(operation, "instance update")

    return instance_client.get(project=project_id, zone=zone, instance=instance_name)


# [END compute_custom_machine_type_update_memory]
